1. Field of the Invention
Cross-flow separators are often used for separating from a liquid particles (also comprising liquid and gas bubbles) suspended therein.
2. State of the Prior Art
A cross-flow separator comprises an assembly of plates arranged at mutually equal distances at an inclination angle, between which plates passages for passing a liquid to be treated are defined, the flow direction of said liquid being directed transversely to the direction of largest inclination of said plates, said plates being provided with profiles defining collecting gutters for the components separated from said liquid by gravity, i.e., because of the fact that said particles are heavier or lighter than the carrier liquid in which they are suspended. Said plates extend substantially in said direction of largest inclination. These collecting gutters open into collecting spaces for said separated components. Cross-flow separators of this kind are shown in U.S. Pat. Nos. 3,837,501 and 4,133,771, both to Jacob Pielkenrood, and assigned to the same assignee as the present patent application.
The currently used cross-flow separators mainly comprise corrugated plates, the corrugation wave height being larger than the average plate distance. The corrugation crests and valleys of adjacent plates respectively are, then, superimposed i.e. in phase. A consequence of the oscillating movement which the liquid is forced to follow is that the flow velocity at which the liquid changes from the laminar into the turbulent condition is lower than in the case of a rectilinear flow in a plate assembly with the same average plate distance. Moreover, the degree of turbulence will, then, increase faster than in the case of a rectilinear flow.
A further drawback of such assemblies of phased corrugated plates is that the streamlined shape of the corrugation crests and valleys will promote entrainment of the already separated particles by the liquid, and the capacity of the collecting gutters defined by the corrugations will be small.
The drawback of the cross-flow separators with flat or plane plates, which have been known for a longer time, in which the liquid flow is substantially rectilinear, is, however, that the separated particles which can slide downwards along the inclined plates will contact the liquid over the whole plate surface, so that the probability of being entrained again by the liquid will be higher accordingly. It has appeared that the separation effect of corrugated plates is better than that of plane plates, but nevertheless, this effect might be still improved.